Crusher jaw

ABSTRACT

A crusher face plate for use in the devices for crushing equipment for rock ore, gravel stock and other like bulk materials. Heretofor devices of this kind utilized a round nose tooth profile and were somewhat inefficient in the use of power. In the present device the tooth profile is provided with several sharp crushing edges which will increase the crushing efficiency per unit power input when used in standard crushing devices.

wnitiffi States aterit I 1 Jette [45] Mar. 27, 1973 l l CRUSHER JAW [75] Inventor: George Alderic .Iette, Calgary, Al-

berta, Canada [73] Assignee: Irving Industries (Foothills Steel Foundry Division) Ltd., Calgary, Alberta, Canada 221 Filed: Jan.26, 1971 21 Appl.No.: 109,893

[30] Foreign Application Priority Data Feb. 5, 1970 Canada ..074l2l [52] US. Cl. ..241/291 [51] Int. Cl ..B02c 1/10 [58] Field of Search ..24l/29l [56] References Cited UNITED STATES PATENTS 2,950,87l 8/1960 Smith ..24l/29l X Ratkowski ..24l/29l Pollitz ..24l/29l X FOREIGN PATENTS OR APPLICATIONS 9 1931 Germany ..241 29i 9/1934 Germany ..24l/29i Primary Exarriiner-Granville Y. Custer, Jr. Att0rneySmart & Biggar [57] ABSTRACT A crusher face plate for use in the devices for crushing equipment for rock ore, gravel stock and other like bulk materials. Heretofor devices of this kind utilized a round nose tooth profile and were somewhat inefficient in the use of power. In the present device the tooth profile is provided with several sharp crushing edges which will increase the crushing efficiency per unit power input when used in standard crushing devices.

6 Claims, 4 Drawing Figures Patented March 27, 1973 3,722,806

FIGZ. FIG.3.

INVENTOR GEORGE A.JETTE ATTORNEYS.

CRUSIIER .IAW

BACKGROUND OF THE INVENTION This invention relates to crushing equipment for rock ore, gravel stock and other like bulk materials and more particularly to tooth profiles for replaceable plates for crushing jaws for such equipment.

There are at least three different types of jaw crusher in common use for bulk material crushing. The first is known as the old style Blake type, the second is known as a modified Blake type and the third is an overhead eccentric type. In all three crusher types, crushing is accomplished by moving a movable jaw relative to a stationary jaw to crush bulk material between the jaws. The jaws of these devices are provided with replaceable face plates having longitudinally extending ribs or teeth, which tend to mate with each other when the jaws are brought towards each other to crush material trapped between them. The ribs or teeth in the past have been formed with a round nose profile cross-section.

In all jaw crushers, there are essentially three major accomplishments that are required for the actual jaw components apart from the general mechanics. First and perhaps foremost, the jaws must crush the bulk material with the least power input. This is particularly true of the old style Blake type jaw crusher. Secondly, the wear factor in design must be of such a degree that a long life is available. Thirdly, a high degree of reliability is mandatory because of the time element required for servicing such major pieces of equipment.

The present invention seeks to provide a tooth profile which will provide more efficient crushing action per unit power input to the crushing machine, and which will provide good resistance to bending and shearing forces.

SUMMARY OF THE INVENTION According to the present invention there is provided a crusher jaw face plate having a series of longitudinally extending teeth in which the tooth cross-sectional profile is a bluntly pointed tip, or major crown, rearwardly and outwardly diverging upper side walls terminating at shoulders, orminor crowns, and lower side walls diverging rearwardly from the shoulders to the tooth roots.

In one embodiment of the present invention the upper and lower side walls are of planar configuration.

In the second embodiment according to-the invention the upper and lower side walls are slightly contoured so as to bow outwardly.

In a further embodiment according to the invention the teeth on the plate are arranged alternatively across the plate with planar and contoured walls.

It is a feature of the invention that the tooth profile instantly expands rearwardly from the tip so as to provide a strong base for resistance to bending and shear forces.

BRIEF DESCRIPTION OF THE DRAWINGS The following is a description by way of example of certain embodiments of the present invention, reference being had to the accompanying drawings in which: I

FIG. 1 is a general side view of a typical jaw crusher of the so-called modified Blake type:

FIG. 2 is a cross-sectional view of one tooth profile according to the present invention;

FIG. 3 is a cross-sectional view of a second tooth profile in accordance with the invention; and

FIG. 4 is a partial cross-sectional view on the lines 4-4 of FIG. 1 of face plates in one crushing operation.

DESCRIPTION oF TH PREFERRED EMBODIMENTS Referring now to the drawings, the modified Blake crusher shown generally in FIG. 1 has a main frame 10 on which is mounted a stationary jaw 12 and a moving jaw 13. The stationary jaw 12 is rigidly attached to the main frame 10 whilst the jaw 13 is mounted for pivotal action about a pivot axis 14 towards and away from the fixed jaw 12 as indicated by the arrows 15. The stationary jaw 12 has a wear plate 17 at its mouth, a loading end, and a removable crushing face plate 19. Similarly the movable jaw 13 has a wear plate 20 at its mouth and a removable crushing face plate 21. Since the general configuration of the crusher device is common the art and forms no part of this invention, it is felt that it is unnecessary here to say more about the general details of the crusher. Also the general overall outer configuration of the face plates, as best seen in FIG. 1, do not form part of this invention, they have the usual deeper and curved lower portions to accommodate for the geometry of swinging one generally flat surface towards another.

Turning to FIGS. 2, 3 and 4, it will be seen that the tooth profile according to the invention has a bluntly pointed tip or major crown 30, rearwardly and outwardlydiverging upper side walls 31 and 32, terminating at shoulders or minor crowns 33, 34, and lower outwardly diverging side walls 35, 36 which merge smoothly into the roots 40 of the teeth. In the embodiment shown in FIG. 2, the walls 31, 32,- 35, 36 are substantially flat or planar, whereas in the embodiment shown in FIG. 3, the walls 31, 32, 35 and 36 are contoured to provide a slightly outwardly bowed face. Generally speaking, a plate will be formed in which all its teeth are of the type seen in FIG. 2 (if hard ores are to be crushed), or, all of the type shown in FIG. 3 (if asofter material, such as limestone, is to be crushed) although for certain specific operations the invention also envisages a plate which will have both types of teeth arranged alternately across the plate.

The operation of the device is best seen with reference to FIG. 4 in which a representative piece of material 42 is being crushed between the jaws 19 and 21. Here the tips 30 of the teeth act against the bulk material to fracture it, creating areas of high pressure at the tips. Because of the high pressure areas the power input to the crusher jaws needs to be less than with conventional tooth profiles. It will also be clearthat'after the initial fracture of the representative piece 42, the now fractured but smaller, portions are further fracturedby a wedgin'g and crushing action on the walls 31 and 32. Then if large or hard pieces of material find their way between the upper parts of the teeth the shoulders 33, 34 acting as minor crowns tend to act as further high pressure areas for reduction of the bulk material. The angles of the walls 31, 32, 35, 36 are in excess of the angle of the repose of the fine or crushed material and hence the material will readily flow to the root area and thence to the discharge portion of the crusher. As has been said the tooth profile becomes larger towards the discharge area of the jaw but the three crown (30, 33, 34) profile is maintained throughout.

In most crushing operations there is a tendency to produce a bending moment in the teeth because of the crushing action of the material between mating teeth apices and teeth roots. The tooth profile of the present invention provides, rearwardly from the tips, an ever increasing thicker and stronger base to which the bending moment will be applied and terminates in a maximum tooth cross-section at the area of maximum combined stress. This increases the life span of the teeth and provides reliability against failure.

In the type of crusher known as an overhead eccentric, motion between the crushing jaws is two-fold, for in addition to the driving of one jaw closer to a stationary jaw, there is component of vertical motion in a downwardly direction which gives rise to a rubbing action between the face plates. The triple crown profile of the present invention is also applicable to this type of motion. The same high pressure areas are created and whilst their pressures are applied, the vertically downward motion creates a cutting action in addition to crushing. The use of the higher pressure areas provide for improved operational results.

What I claim as my invention is:

l. A crusher jaw face plate having a series of longitudinally extending teeth in which the tooth cross-sectional profile is a bluntly pointed tip, rearwardly and outwardly diverging upper side walls, terminating at shoulders and lower sidewalls diverging outwardly and rearwardly from the shoulders and terminating in a smooth concave radius at the tooth roots for interacting co-operation with a similar opposing jaw face plate.

2. A device as claimed in claim 1 in which the upper and the lower side walls are flat.

3. A device as claimed in claim 1 in which the upper and lower side walls are contoured to slightly bow outwardly. I

4. A device as claimed in claim 1 in which each tooth is widest adjacent its roots.

5. A device as claimed in claim 1 in which said teeth alternate across the face plate between, teeth having upper and lower flat sidewalls, and, teeth having upper and lower sidewalls which are bowed slightly outwardly.

6. A device as claimed in claim 1 in which the tooth profile is maintained throughout the jaw crushing face plate. 

1. A crusher jaw face plate having a series of longitudinally extending teeth in which the tooth cross-sectional profile is a bluntly pointed tip, rearwardly and outwardly diverging upper side walls, terminating at shoulders and lower sidewalls diverging outwardly and rearwardly from the shoulders and terminating in a smooth concave radius at the tooth roots for interacting co-operation with a similar opposing jaw face plate.
 2. A device as claimed in claim 1 in which the upper and the lower side walls are flat.
 3. A device as claimed in claim 1 in which the upper and lower side walls are contoured to slightly bow outwardly.
 4. A device as claimed in claim 1 in which each tooth is widest adjacent its roots.
 5. A device as claimed in claim 1 in which said teeth alternate across the face plate between, teeth having upper and lower flat sidewalls, and, teeth having upper and lower sidewalls which are bowed slightly outwardly.
 6. A device as claimed in claim 1 in which the tooth profile is maintained throughout the jaw crushing face plate. 